Not Applicable
1. Field of the Invention
The present invention relates to novel bicyclic tris(anhydride)s (BTAs) useful as intermediates in the synthesis of biologically active compounds, and the compounds which may be synthesized from such intermediates.
2. Description of Related Art
P1,P2-disubstituted pyrophospate derivatives play an important role in a variety of biochemical transformations. For example, nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD) serve as the major electron carriers in biological dehydrogenations, whereas another pyrophosphate, coenzyme A (CoA), is a universal carrier of acyl groups. Cytidine diphosphodiacylglycerol (CDP-diacylglycerol), cytidine diphosphocholine (CDP-choline) and cytidine diphosphoethanolamine (CDP-ethanolamine) are activated intermediates in the de novo synthesis of various phospholipids. UDP-glucose, UDP-galactose as well as some purine dinucleotide sugars such as GDP-mannose serve as cofactors in many sugar transfer processes. Finally, mono- and poly(ADP-ribose) derivatives which modulate the function of proteins, as well as cyclic ADP-ribose which influences calcium metabolism, also contain the pyrophosphate moiety.
It has long been sought to develop a simple method to synthesize isosteric methylenebis(phosphonate) analogues of the above biologically important P1,P2-disubstituted pyrophosphates, because such analogues, in which the pyrophosphate oxygen is replaced by a methylene group, preserve the shape, size and electronic charge of the natural counterpart significantly, and provide derivatives with modified biochemical properties at a particular site. For example, in contrast to the pyrophosphate bond (P1xe2x80x94Oxe2x80x94P2), the P1xe2x80x94CH2xe2x80x94P2 linkage of methylenebis(phosphonate)s cannot be hydrolyzed by the enzymes that cleave the pyrophosphate bond. Another advantage of phosphonates as phosphate mimics is their ability to penetrate cell membranes (Miller and Tso, Anti-Cancer Drug Design, 1987, 2, 117; Bergstrom, et al., Nucleosides, Nucleotides, 1987, 6, 53; Bergstrom and Shum, J. Org. Chem., 1988, 53, 3953).
Currently, no practical method is available for the synthesis of P1, P2-disubstituted methylenebis(phosphonate) analogues of natural cofactors and ADP-ribose derivatives. Only a few such compounds have been synthesized in low yields after lengthy and tedious processes. For example, methylenebis(phosphonate) analogues of ADP-glucose, UDP-galactose, and GDP-mannose were prepared as potential inhibitors of glycosyl transferase. Activation of the corresponding pyranosyl-1-methylenebis(phosphonate) with 1-(mesitylene-2-sulfonyl)-3-nitro-1,2,4-triazole (MSTN) and coupling with an appropriate nucleoside derivative afforded the desired compounds only in moderate yields (32-48%) which made the isolation of pure compounds a rather difficult and time consuming process (Vaghefi, et al., J. Med. Chem. 1987, 30, 1391). The methylenebis(phosphonate) analogue of tiazole-4-carboxamide adenine dinucleotide, xcex2-methylene-TAD, was synthesized in 36% yield by dicyclohexylcarbodiimide (DCC) catalyzed coupling of protected tiazofurin with adenosine 5xe2x80x2-methylene bis(phosphonate). Again, purification of this compound from the mixture was quite cumbersome. It was found that xcex2-methylene TAD is a potent inhibitor of inosine monophosphate dehydrogenase (IMPDH) (Marquez, et al., J. Med. Chem. 1986, 29, 1726).
Inosine monophosphate dehydrogenase (IMPDH) catalyzes the NAD dependent conversion of inosine 5xe2x80x2 monophosphate (IMP) to xanthosine monophosphate. Two forms of the enzyme are found in mammalian cells, each encoded by distinct cDNAs (Natsumeda, Y. et al., J. Biol. Chem., 1990,265, 5292-5295). Type I is expressed constitutively, while the levels of type II are markedly increased in tumor cells and activated lymphocytes conversely, when tumor cells are induced to differentiate, transcripts of type II decline to below those of type I.
Mycophenolic acid (MPA) is the most potent inhibitor of IMPDH (Carr, et al. J. Biol. Chem. 1993, 268, 27286-27290). It blocks B and T lymphocyte proliferation and has been used as an immunosuppressant (Wu, J. C. In Perspectives in Drug Discovery and Design, Wyvratt, M. J.; Sigal, N. H., Eds.; ESCOM Science Publ., Leiden, 1994, Vol. 2, pp 185-204), although it is inactive against tumors due to its quick conversion into the inactive xcex2-glucuronide after administration (Franklin, et al. Cancer Res., 1996, 56, 984-987). MPA inhibits IMPDH with even better specificity against the type II isoform dominant in cancer cells (Ki=6-10 nM) than type I expressed in normal cells (Ki=33-37 nM) (Carr, et al., loc cit.). When the MPA binds to the cofactor moiety of IMPDH, it resembles that of nicotinamide mononucleotide (NMN) with a carboxyl group positioned at the space occupied by the phosphoryl group of NMN (Sintchak, et al., Cell, 1996, 85, 921-930).
In one aspect, the present invention relates to a compound having the following structure: 
wherein
Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, a mycophenolic acid residue or derivative, steroid, or substituted glyceride; and
X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl.
In another aspect, the present invention provides a method for the preparation of a compound having the following structure: 
wherein
Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, a mycophenolic acid residue or derivative, steroid, or substituted glyceride; and
X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl;
which method comprises reacting a compound having the following structure: 
wherein Z and X are as described, with a dehydrating agent.
In another aspect, the present invention provides a method for the preparation of a compound having the following structure: 
wherein
Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, a mycophenolic acid residue or derivative, steroid, or substituted glyceride; and
X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl;
which method comprises reacting a compound having the following structure: 
wherein Z, Z1 and X are as defined above, with a dehydrating agent.
In another aspect, the present invention provides a method for the preparation of a compound having the following structure: 
wherein
Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, steroid, a mycophenolic acid residue or derivative or substituted glyceride; and
X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl;
which method comprises reacting a compound having the following structure: 
wherein Z, Z1 and X are as defined above, with a nucleophilic agent.
In another aspect, the present invention provides compounds having the following structure: 
wherein
Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, steroid, a mycophenolic acid residue or derivative, or substituted glyceride; and
X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl.
In another aspect, the present invention provides compounds having the following structure: 
wherein
each of R1, R2, R3, and R4 is independently H, OH or F;
X is O, S, mono- or di-halomethylene, or NR wherein R is H or alkyl, or CH2;
Y is OH, SH or F; and
each of W1 and W2 is independently H, OH, xe2x95x90O, OR, SH, SR, NH2, NHR or NR2, wherein R is C1-C5 alkyl and n is an integer from 1 to 5.
The present invention provides new, versatile intermediates for synthesis of numerous P1,P2-disubstituted methylene- and mono- or difluoro- or amino-methylene-bis(phosphonate)s of biological importance. The intermediate compounds may be prepared by action of a dehydrating agent on a P1-mono-substituted phosphonomethylenephosphonate (Zxe2x80x94P1xe2x80x94CH2xe2x80x94P2xe2x80x94OH or Zp2) having the following structure: 
wherein Z is aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, steroid, or substituted glyceride; and X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl. There are many suitable dehydrating agents which would be apparent to one of ordinary skill. Preferred dehydrating agents include carbodiimides, particularly 1,3-dicyclohexylcarbodiimide (DCC) or 1,3-diisopropylcarbodiimide.
The intermediates of the present invention may also be prepared by dehydration of a P1,P4-disubstituted-P1:P2,P2:P4-dimethylene tetrakis(phosphonic) anhydride (Zxe2x80x94P1xe2x80x94CH2xe2x80x94P2xe2x80x94Oxe2x80x94P3xe2x80x94CH2xe2x80x94P4xe2x80x94Z1 or Zp4Z1) having the following structure: 
wherein Z and Z1 are the same or different and are alkyl, aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, a mycophenolic acid residue or derivative, steroid, or substituted glyceride; and X is methylene (xe2x80x94CH2xe2x80x94), mono- or di-halo methylene, or xe2x80x94NRxe2x80x94, where R is H or alkyl.
The above Zp4Z1 analogues can be prepared from the corresponding methylenebis(phosphonate)s (Zp2 or Z1p2) by reaction with a dehydrating agent, such as DCC, to give a symmetrical Zp4Z or Z1p4Z1. Alternatively, the Zp2 can be activated with imidazole and reacted with Z1p2 to give an unsymmetrical derivative Zp4Z1: 
Such an unsymmetrical tetrakis(phosphonate) analogue can be further dehydrated to give the corresponding mixed bicyclic tris(anhydride), BTA, which upon reaction with an appropriate nucleophilic reagent Z2 gives two different pyrophosphate analogues: Zp2Z2 and Z1p2Z2. 
wherein Z2 is aralkyl, aryl, aminoalkyl, alkyloxy, aralkyloxy, alkylamino, aralkylamino, arylamino, alkylmercaptan, aralkylmercaptan, arylmercaptan, carbohydrate, nucleoside, a mycophenolic acid residue or derivative, steroid, or substituted glyceride; and X is as described above.
During the course of studies on the reaction of 2xe2x80x2,3xe2x80x2-O-isopropylideneadenosin-5xe2x80x2-ylphosphonomethylenephosphonic acid (1, Scheme 1) with DCC, the inventors developed a very unique intermediate with the bicyclic [3.3.1] system (4) which is highly susceptible to nucleophilic attack to produce readily a number of P1,P2-disubstituted methylenebis (phosphonate)s. Scheme 1 exemplifies the synthesis of a P1-(adenosin-5xe2x80x2-yl)-P2-(benzyl xcex2-D-ribofuranosid-5-yl)-methylenebis(phosphonate) derivative 7 in very high yield with a novel mechanism. 
Reaction of (1, Ap2) with DCC afforded bis(2xe2x80x2,3xe2x80x2-O-isopropylidene-adenosine-5xe2x80x2-phosphonomethylenephosphonyl)anhydride (2), an analogue of P1,P4-diadenosine tetraphosphate (Ap4A) which was reported by Blackburn et al. (Blackburn, G. M.; Guo, M-J.; McLennan, A. G. in xe2x80x9cAp4A and Other Dinucleoside Polyphosphatesxe2x80x9d, McLennan, A. G. ed., CRC Press, Inc., Boca Raton, 1994, Chapter 11, pp. 313-314). However, when 3-4 equivalents of DCC were used, it was discovered that P1,P3-dehydration of 2 took place leading to the formation of cyclic anhydride 3. Moreover, further dehydration between P2 and P4 occurred surprisingly to give rise to bicyclic trisanhydride (BTA) 4. Such BTA could be also prepared from isolated Ap4A analogue 2. The uncharged BTA 4 could not be isolated due to its susceptibility to hydrolysis. However, its presence could be detected by 31P NMR. Thus, the 31P NMR spectrum of 4 contained multisignal resonances in three broad regions of d xe2x88x920.5-2.2, 6.0-8.0, and 12.8-17.6 ppm. Since all four phosphorus atoms in the structure of 4 are chiral, such multisignal resonances should be expected. The non-equivalence of phosphorus atoms P1 and P4 in the bicyclic structure of 4 is further extended due to substitution on P1 and P4 by the chiral adenosyl moiety. All these characteristics contribute to such complicated phosphorus NMR feature.
The assignment of the structure of BTA 4 was further confirmed by its hydrolysis with H218O to the corresponding Ap4A analogue 2 and further to the starting monoester of methylenebis(phosphonic) acid 1. These compounds were separated by preparative HPLC and subjected to MS (ES) analyses. The molecular weight of 2 was established as 916 by the presence of the Mxe2x88x92H ion at m/z 915 and doubly charged (Mxe2x88x922H)xe2x88x922 at m/z 457. Thus, the conversion of 4 into 2 resulted, as expected, in incorporation of two H218O molecules. The MS of monoester of methylenebis(phosphonic acid) 1 indicated the incorporation of one or two 18O atoms by the presence of Mxe2x88x92H ion at m/z 466 and 468.
The chemical reactivity of BTA 4 also confirmed its structure assignments. Reaction of 4 with benzyl 2,3-O-isopropylidene-xcex2-D-ribofuranoside 8 occurred smoothly due to the uncharged BTA 4. Thus, the corresponding ester of P1,P2,P3,P4-bis(methylenebisphosphonate) analogue of Ap4A (6) was detected as a single product by 31P NMR. The multisignal resonances of 4 collapsed into two broad signals of 6 showing the characteristic AAxe2x80x2XXxe2x80x2 system of Ap4A analogues. Such reactivity can be explained by the greater susceptibility of phosphorus atoms P2 and P3 than P1 and P4 in the bicyclic structure of 4 to nucleophilic attack. Indeed, this should be expected since not only do adenosine moieties provide steric hindrance for P1 and P4 but also electronic effects favor attacking the P2 and P3 atoms rather than P1 and P4. The P2 and P3 phosphorus atoms of 4 are connected through the pyrophosphate bond to each other and to the P4 and P1, respectively, through the second pyrophosphate linkage. Therefore, the P2 and P3, which participate in the formation of such phosphorus bisanhydride, are more electron deficient (i.e., more susceptible to nucleophilic attack) than the corresponding P1 and P4 atoms linked to adenosine via ester bond. The stoichiometry of 4 to 6 conversion shows that substitution of phosphorus P2 (alternatively P3) should result in the formation of intermediate 5 by breaking the P2xe2x80x94Oxe2x80x94P4 (or P1xe2x80x94Oxe2x80x94P3) pyrophosphate bond rather than P2xe2x80x94Oxe2x80x94P3 linkage. The pyrophosphate bond P2xe2x80x94Oxe2x80x94P3 in 5 is left intact to allow the second nucleophilic attack of 8 on still uncharged phosphorus atom P3 of 5 to give derivative 6. Alternatively, the concerted attack on P2 and P3 atoms would also give derivative 6 (see Scheme 1).
After hydrolysis with water, two equivalents of the desired ADP-ribose derivative 7 were obtained from one molecule of 6 in almost quantitative yield. Gram amounts of ADP-ribose derivative 7 can be obtained by this procedure since the crude product does not require HPLC purification.
The same ADP-ribose 7 can be obtained by activation of benzyl 2,3-O-isopropylidene xcex2-D-ribofuranosid-5-yl-phosphonomethylenephosphonic acid (9) with DCC followed by reaction with 2xe2x80x2,3xe2x80x2-O-isopropylidene-adenosine (11). The active intermediate is now BTA 10. 
In a similar manner the reaction of BTA 4 with 2,3-O-isopropylidene D-ribonolactone 12 afforded the methylene-bis(phosphonate) analogue of ADP-ribonolactone 13. ADP-ribonolactone is the known transition state inhibitor of ADP-ribosylation. 
In a similar manner riboflavine (14) reacted with BTA 4 to give the corresponding methylenebis(phosphonate) analogue of flavin adenine dinucleotide (FAD). 
Similarly, reaction of BTA 4 with pantothenic acid derivative (16) afforded the methylenebis(phosphonate) analogue related to dephospho CoA (17). 
The formation of such BTAs is not limited to 4 or 10. Virtually any monosubstituted methylenebis(phosphonate) Zp2 (wherein Z can be alkyl, alkyloxy, carbohydrate, nucleoside, terpene, etc.) or the tetraphosphate analogue Zp4Z (Z defined above) can be converted into the corresponding BTA. For example, 2xe2x80x2,3xe2x80x2-O-isopropylidene-N-acetylcytidin-5xe2x80x2-yl-methylenebis(phosphonate) (18) was converted into the corresponding BTA (19) which upon reaction with N-acetylethanolamine (20) afforded the methylenebis(phosphonate) analogue of CDP-ethanolamine 21. 
Similar reaction of BTA 19 with diacylglycerol 22 yielded the corresponding CDP-diacylglycerol analogue 23. 
The formation of BTAs is not limited to methylene bisphosphonates. A similar dehydratation was found to occur with difluoromethylenebis(phosphonate)s. For example, 2xe2x80x2,3xe2x80x2-O-isopropylidene-tiazofurin-5xe2x80x2-yl-difluoromethylenebis(phosphonate) (24) was converted into the corresponding BTA 25, which on treatment with adenosine derivative 11 produced the analogue of TAD 26. 
Utilization of BTAs is not limited to reactions with a variety of compounds containing hydroxyl group (Rxe2x80x94OH), leading to the formation of methylene- or difluoromethylenebisphosphonates of biological interest as will be shown in the examples. Virtually, any nucleophilic reagent, such as Phxe2x80x94OH, Phxe2x80x94SH, Rxe2x80x94SH, Rxe2x80x94NH2, R2NH, etc. reacts with BTAs to give the corresponding P1,P2-disubstituted bis(phosphonate)s.
Also, reaction of BTAs with phosphoric, phosphonic, and phosphinic acid derivatives give the corresponding triphospate analogues: 
Utilization of BTAs is not limited to intermolecular reactions. Intramolecularly attached nucleophilic groups can also participate in formation of cyclic derivatives according to the principle of this invention. This is further demonstrated in Scheme 2 by the synthesis of analogues of cyclic IDP-ribose in which the ribose at N1 is replaced by butanol. Thus, 2xe2x80x2,3xe2x80x2-O-isopropylideneinosine (27) was alkylated with 4-bromobutyl acetate in the presence of DBU to give a 9:1 mixture of N1- and O6-substituted products 28 and 31, respectively. Compounds 28 and 31 were separated on a column of silica gel and then mesylated to give 5xe2x80x2-mesylates 29 and 32. Upon treatment with the tetrabutylammonium salt of methylenebis-(phosphonic) acid followed by deacetylation, 29 and 32 were converted into their corresponding methylenebis-(phosphonate)s 30 and 33 from which the corresponding BTAs 34 and 35 were prepared as described in Example 1. Formation of BTAs was found to be much faster than the subsequent reaction with butanol attached to N1 or O6 of 34 and 35, respectively. Yield of the desired analogues of cyclic IDP ribose 36 and by-product 37 was 10-14%. 
Particularly preferred compounds with the present invention include analogs of mycophenolic purine dinucleotide having the following general structure (A): 
wherein
each of R1, R2, R3, and R4 is independently H, OH or F;
X is O, S, mono- or di-halomethylene, or NR wherein R is H or alkyl, or CH2;
Y is OH, SH or F; and
each of W1 and W2 is independently H, OH, xe2x95x90O, OR, SH, SR, NH2, NHR or NR2, wherein R is C1-C5 alkyl and n is an integer from 1 to 5.
The mycophenolic acid derivatives (structure (A) above) of the present invention have inhibitory activity against IMPDH-II, and are resistant to inactivation by glucuronidation with various glucuronyltransferases in vitro, and also stable in plasma at room temperature for at least several days. They may thus be used as immunosuppressants, and to treat conditions associated with elevated levels of IMPDH, such as cancer, especially certain leukemias including lymphocytic leukemia or chronic granulocytic leukemia.
The structure (A) compounds of the present invention may be synthesized by linking a nucleoside-5xe2x80x2-methylenebis-(phosphonate) to various mycophenolic alcohols (MPols) of general structure 2 
using methods disclosed herein.
Treatment of 2xe2x80x2,3xe2x80x2-O-isopropylidene nucleoside 5xe2x80x2-methylenebis(phosphonate)s in general and the adenosine derivative 3 (Scheme 3 below) in particular with diisopropylcarbodiimide (DIC) leads to the formation of P1, P4-bis(adenosin-5xe2x80x2-yl)tetraphosphonate 4, which upon further dehydration with DIC is converted into an active intermediate 5 having the structure of bicyclic trisanhydride (Pankiewicz, K. W. et al., J. Am. Chem. Soc., 1997, 119, 3691-3695). Reaction of the bicyclic intermediate 5 with an MP-n-ol 2 gives the corresponding P2, P3-bis (mycophenolic alcohol-6-yl)-P1, P4-di-(2,3-O-isopropylidene-adenosin-5xe2x80x2-yl)tetraphosphonates 6 which upon hydrolysis with water and deisopropylidenation with acid afford the desired P1-adenosine-5-yl, P2-mycophenolic alcohol-6-yl methylenebis(phosphonate) (xcex2-methylene MAD 1).
The structure of 1 (n=3, for example) is established by 1H and 31P NMR and MS (see Experimental Details). The resonance signal of 6xe2x80x2CH2 of the MP-n-ol (n=3) moiety in the proton NMR of 1 at 3.79 appeared as a quartet (JH-P=6.3 Hz and JH-H=6.3 Hz) showing the coupling with the phosphorus atom. A heteronuclear shift correlation experiment also confirmed the phosphorus-6xe2x80x2CH2 coupling. 
The compounds of structure 1 are stable in plasma at room temperature for at least several days. It is assayed for both inhibitory activity against human IMPDH type II and for anti-proliferative activity against K562 erythroleucemic cells. The IC50 values are measured in the presence of 100 xcexcM NAD, 50 xcexcM IMP, 100 nM Tris-HCl, 100 mM KCl, 3 mM EDTA, and 25 nM enzyme at pH 8.0. The ability to induce differentiation in K562 cells is also estimated by determining the fraction of benzidine positive cells converted following incubation with xcex2-methylene-MAD. It is found that this compound is a potent inhibitor of IMPDH type II with Ki=0.3 xcexcM as well as growth of K562 cells with IC50=6 xcexcM. In addition, this compound was found to be completely resistant to glucuronidation by various glucuronosyltransferases in contrast to mycophenolic acid which is effectively glucuronidated in parallel experiments.
Compounds within the present invention will have biological activity and thus may be administered to patients in need thereof. For therapeutic or prophylactic treatment, the compounds of the present invention may be formulated in a pharmaceutical composition, which may include, in addition to an effective amount of active ingredient, pharmaceutically acceptable carriers, thickeners, diluents, buffers, preservatives, surface active agents and the like. Pharmaceutical compositions may also include one or more other active ingredients if necessary or desirable.
The pharmaceutical compositions of the present invention may be administered in a number of ways as will be apparent to one of ordinary skill. Administration may be done topically, orally, by inhalation, or parenterally, for example.
Topical formulations may include ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Oral formulations include powders, granules, suspensions or solutions in water or non-aqueous media, capsules or tablets, for example. Thickeners, flavorings, diluents, emulsifiers, dispersing aids or binders may be used as needed.
Parenteral formulations may include sterile aqueous solutions which may also contain buffers, diluents and other suitable additives.
The dose regimen will depend on a number of factors which may readily be determined, such as severity and responsiveness of the condition to be treated, but will normally be one or more doses per day, with a course of treatment lasting from several days to several months, or until a cure is effected or a diminution of disease state is achieved. One of ordinary skill may readily determine optimum dosages, dosing methodologies and repetition rates. In general, it is contemplated that unit dosage form compositions according to the present invention will contain from about 0.01 mg to about 500 mg of active ingredient, preferably about 0.1 mg to about 10 mg of active ingredient. Topical formulations (such as creams, lotions, solutions, etc.) may have a concentration of active ingredient of from about 0.01% to about 50%, preferably from about 0.1% to about 10%.
The following examples are illustrative of the processes and products of the present invention, but are not to be construed as limiting.